1. Field of the Invention
The present invention relates to a memory device, and more particularly to an extension positioning structure for a portable memory device.
2. Description of the Prior Art
Memory devices which are generally referred to as traveling disks become more and more popular due to large storage capacity and small volume. A common traveling disk normally comprises a memory unit with a connecting terminal and a shell for protecting the memory unit. The connecting terminal of many of the current traveling disks is extensible or retractable with respect to the shell.
Conventionally, the connecting terminal of the traveling disk is linearly pushed to slide in the shell to perform the extending and retracting operation. Since there is no buffer structure in the traveling disk, the linear pushing force applied to the connecting terminal will cause wear of the push rod or the cooperating rail, consequently resulting in loss of the extending and retracting function of the connecting terminal and causing damage to the internal structure.
In addition, some of the conventional traveling disks don't have any positioning structure to keep the connecting terminal in the extended and retracted positions, and for these conventional traveling disks without positioning structures, when inserting the connecting terminal into the transmission port, the user has to apply force to the push rod in order to prevent the connecting terminal from retracting in the shell. To solve the above problem, the traveling disk is formed with a positioning structure on an inner surface thereof by injection molding. However, such a positioning structure which employs a concave structure cooperating with a convex structure to fix the connecting terminal to the shell won't have a good positioning effect since the shell is made of plastic and deformable.
Two conventional memory devices are provided herein for reference. As for a first conventional memory device, since the traveling disk has a small volume and a much smaller internal structure, when the user applies an improper force, a damage beyond repair will be caused to the internal structure. Therefore, a second conventional memory device disclosed an extending and retracting traveling structure which consists of many elements, it is a complicated structure and inconvenient to assemble. In addition, its complicated structure will further cause a relatively low yield rate.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.